Corpus overview


Overview

MeSH Disease

Human Phenotype

Fever (2)

Cough (1)

Anosmia (1)


Transmission

Seroprevalence
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    Estimating Asymptomatic TRANS and Undetected Cases in the COVID-19 Outbreak in Wuhan

    Authors: Xi Huo; Jing Chen; Shigui Ruan

    doi:10.21203/rs.3.rs-75913/v1 Date: 2020-09-11 Source: ResearchSquare

    Background: The COVID-19 outbreak in Wuhan started in December 2019 and was under control by the end of March 2020 with a total of 50,006 confirmed cases TRANS by the implementation of a series of nonpharmaceutical interventions (NPIs) including unprecedented lockdown of the city. This study analyzes the complete outbreak data from Wuhan, assesses the impact of these public health interventions, and estimates asymptomatic TRANS and undetected cases in the outbreak.Methods: By taking different stages of the outbreak into account, we developed a time-dependent compartmental model to describe the dynamics of disease transmission TRANS and case detection and reporting. Model coefficients were parameterized by using the reported cases and following key events and escalated control strategies. Then the model was used to calibrate the complete outbreak data by using the Monte Carlo Markov Chain (MCMC) method. Finally we used the model to estimate asymptomatic TRANS and undetected cases and approximate the overall antibody SERO prevalence SERO level.Results: We found that the transmission TRANS rate between Jan 24 and Feb 1 was twice as large as that before the lockdown on Jan 23 and 67.6% (95% CI [0.584; 0.759]) of detectable infections occurred during this period.. Based on the reported estimates that around 20% of infections were asymptomatic TRANS and their transmission TRANS ability was about 70% of symptomatic ones, we estimated that there were about 14,448 undetected cases (95% CI [12,364; 23,254]), which yields an estimate of a total of 64,454 infected cases (95% CI [62,370; 73,260]), and the overall antibody SERO prevalence SERO level in the population of Wuhan was 0.745% (95% CI [0.693%, 0.814%]) by March 31, 2020.Conclusions: We conclude that the control of the COVID-19 outbreak in Wuhan was achieved via the enforcement of a combination of multiple NPIs: the lockdown on Jan 23, the stay-at-home order on Feb 2, the massive isolation of all symptomatic individuals via newly constructed special shelter hospitals on Feb 6, and the large scale screening process on Feb 18. Our results indicate that the population in Wuhan is far away from establishing herd immunity and provide insights for other affected countries and regions in designing control strategies and adjusting reopen plans.

    Susceptibility of swine cells and domestic pigs to SARS-CoV-2

    Authors: David A Meekins; Igor Morozov; Jessie D Trujillo; Natasha N Gaudreault; Dashzeveg Bold; Bianca L Artiaga; Sabarish V Indran; Taeyong Kwon; Velmurugan Balaraman; Daniel W Madden; Heinz Feldmann; Jamie Henningson; Wenjun Ma; Udeni B.R. Balasuriya; Juergen A Richt

    doi:10.1101/2020.08.15.252395 Date: 2020-08-16 Source: bioRxiv

    The emergence of SARS-CoV-2 has resulted in an ongoing global pandemic with significant morbidity, mortality, and economic consequences. The susceptibility of different animal species to SARS-CoV-2 is of concern due to the potential for interspecies transmission TRANS, and the requirement for pre-clinical animal models to develop effective countermeasures. In the current study, we determined the ability of SARS-CoV-2 to (i) replicate in porcine cell lines, (ii) establish infection MESHD in domestic pigs via experimental oral/intranasal/intratracheal inoculation, and (iii) transmit to co-housed naive sentinel pigs. SARS-CoV-2 was able to replicate in two different porcine cell lines with cytopathic effects. Interestingly, none of the SARS-CoV-2-inoculated pigs showed evidence of clinical signs, viral replication or SARS-CoV-2-specific antibody SERO responses. Moreover, none of the sentinel pigs displayed markers of SARS-CoV-2 infection MESHD. These data indicate that although different porcine cell lines are permissive to SARS-CoV-2, five-week old pigs are not susceptible to infection via oral/intranasal/intratracheal challenge. Pigs are therefore unlikely to be significant carriers TRANS of SARS-CoV-2 and are not a suitable pre-clinical animal model to study SARS-CoV-2 pathogenesis MESHD or efficacy of respective vaccines or therapeutics.

    Presymptomatic Transmission TRANS and Diverse Progression of Familial Clustering Covid-19 Cases in Zhoushan, China

    Authors: Miao Liu; Leijie Liu; Ping Li; Yibo Ding; Ting Wu; Weina Tang; Zhongfa Wang; Guangwen Cao

    doi:10.21203/rs.3.rs-44177/v1 Date: 2020-07-16 Source: ResearchSquare

    Background Novel coronavirus disease MESHD 2019 (COVID-19), severe acute respiratory syndrome coronavirus 2 MESHD (SARS-CoV-2)-caused emerging infectious disease MESHD, firstly identified in Wuhan (Hubei, China), is pandemic. However, data concerning presymptomatic SARS-CoV-2 transmission TRANS and disease diversity among family members TRANS are limited. Herein, We investigated the epidemiological and clinical characteristics of presymptomatic transmission TRANS-caused familial clustering cases of SARS-CoV-2 infection MESHD in Zhoushan island, China.Methods All family members TRANS were tested for SARS-CoV-2 genomic RNA by quantitative reverse transcription PCR in 3 different samples and serum SERO antibody SERO immunoglobin M (IgM) and IgG against SARS-CoV-2. Exposure identification, laboratory test, and imaging were performed according to the national guideline of COVID-19 (7th edition, China).Results Of the 6 cases, index case who ever met his relative with COVID-19 from Xianning, Hubei on January 26–31, 2020, transmitted SARS-CoV-2 to his family members TRANS in Zhoushan via visiting family during January 31 and February 3, 2020. The index was identified as common-type COVID-19 on February 6, 2020. All 5 family members TRANS were infected with SARS-CoV-2. Of those, a 7-year-old girl was an asymptomatic TRANS carrier TRANS whereas her grandparents, especially her grandfather, were very sick. Case 6 (grandfather) remained positive for SARS-CoV-2 RNA in his sputum specimen in subsequent 2 months. Case 2 (mother) tested negative for SARS-CoV-2 RNA in all samples but positive for IgM and IgG to SARS-CoV-2 since February 9, 2020.Conclusions Presymptomatic transmission TRANS of SARS-CoV-2 causes familial cluster of COVID-19. Exposed to the same source of infection MESHD, family members TRANS present their differences in disease severity and viral clearance.

    Community-level SARS-CoV-2 Seroprevalence SERO Survey in urban slum dwellers of Buenos Aires City, Argentina: a participatory research.

    Authors: Silvana Figar; Vanina Pagotto; Lorena Luna; Julieta Salto; Magdalena Wagner Manslau; Alicia Mistchenko; ANDREA GAMARNIK; Ana Maria Gomez Saldano; Fernan Quiros

    doi:10.1101/2020.07.14.20153858 Date: 2020-07-16 Source: medRxiv

    Background By July 1st, the incidence rate of RT-qPCR SARS-CoV-2 infection was 5.9% in Barrio Padre Mugica, one of the largest slums in Buenos Aires City. This study aimed to establish the seroprevalence SERO of SARS-CoV-2 three months after the first case was reported. Methods Between June 10th and July 1st, a cross-sectional design was carried out on people over 14 years old, selected from a probabilistic sample of households. A finger prick sample was tested by ELISA SERO to detect IgG-class antibodies SERO against SARS-CoV-2. Multilevel model was applied to understand sector, household and individual conditions associated with seroconvert. Results Prevalence SERO based on IgG was 53.4% (95%IC 52.8% to 54.1%). Among the IgG positive cases, 15% reported having compatible symptoms at some point in the past two months. There is evidence of within-household clustering effect (rho=0.52; 95% IC 0.36-0.67); living with a PCR- confirmed case TRANS doubled the chance of being SARS-CoV2 IgG positive (OR 2.13; 95% IC 1.17-3.85). The highest risk of infection TRANS risk of infection TRANS infection MESHD was found in one of the most deprived areas of the slum, the Bajo autopista sector. Discussion High seroprevalence SERO is shown, for each symptomatic RT-qPCR-confirmed diagnosis, 9 people were IgG positive, indicating a high rate of undetected (probable asymptomatic TRANS) infections. Given that transmission TRANS among family members TRANS is a leading driver of the disease`s spread, it is unsurprising that crowded housing situations in slums are directly associated with higher risk of infection TRANS risk of infection TRANS infection MESHD and consequently high seroprevalence SERO levels. This study contributes to the understanding of population immunity against SARS-CoV2, its relation to living conditions and viral spread, for future decision making.

    Antibody SERO dynamics to SARS-CoV-2 in Asymptomatic TRANS and Mild COVID-19 patients

    Authors: Qing Lei; Yang Li; Hongyan Hou; Feng Wang; Yandi Zhang; Danyun Lai; Banga Ndzouboukou Jo-Lewis; Zhaowei Xu; Bo Zhang; Hong Chen; Zhuqing Ouyang; Junbiao Xue; Xiaosong Lin; Yunxiao Zheng; Zhongjie Yao; Xuening Wang; Caizheng Yu; Jeremy Jiang; Hainan Zhang; Huan Qi; Shujuan Guo; Shenghai Huang; Ziyong Sun; Sheng-ce Tao; Xionglin Fan

    doi:10.1101/2020.07.09.20149633 Date: 2020-07-11 Source: medRxiv

    Abstract Importance Asymptomatic TRANS COVID-19 infections have a long duration of viral shedding and contribute substantially to disease transmission TRANS. However, the missing asymptomatic TRANS cases have been significantly overlooked because of imperfect sensitivity SERO of nucleic acid testing. We aimed to investigate the humoral immunity in asymptomatics TRANS, which will help us develop serological tests SERO and improve early identification, understand the humoral immunity to COVID-19, and provide more rational control strategies for the pandemic. Objective To better control the pandemic of COVID-19, dynamics of IgM and IgG responses to 23 proteins of SARS-CoV-2 and neutralizing antibody SERO in asymptomatic TRANS COVID-19 infections after exposure time were investigated. Design, setting, and participants 63 asymptomatic TRANS individuals were screened by RT-qPCR and ELISA SERO for IgM and IgG from 11,776 personnel returning to work, and close contacts TRANS with the confirmed cases TRANS in different communities of Wuhan by investigation of clusters and tracing TRANS infectious sources. 63 healthy contacts with both negative results for NAT and antibodies SERO were selected as negative controls. 51 mild patients without any preexisting conditions were also screened as controls from 1056 patients during hospitalization in Tongji Hospital. A total of 177 participants were enrolled in this study and serial serum samples SERO (n=213) were collected. The research was conducted between 17 February 2020 and 28 April 2020. Serum SERO IgM and IgG profiles of 177 participants were further probed using a SARS-CoV-2 proteome microarray. Neutralizing antibody SERO responses in different population were detected by a pseudotyped virus neutralization assay system. The dynamics of IgM and IgG antibodies SERO and neutralizing antibodies SERO were analyzed with exposure time or symptoms onset TRANS. Results Asymptomatics TRANS were classified into four subgroups based on NAT and serological tests SERO. In particular, only 19% had positive NAT results while approximately 81% detected positive IgM/IgG responses. Comparative SARS-CoV-2 proteome microarray further demonstrated that there was a significantly difference of antibody SERO dynamics responding to S1 or N proteins among three populations, although IgM and IgG profiles could not be used to differentiate them. S1 specific IgM responses were elicited in asymptomatic TRANS individuals as early to the seventh day after exposure and peaked on days from 17d to 25d, which might be used as an early diagnostic biomarker and give an additional 36.5% seropositivity. Mild patients produced stronger both S1 specific IgM and neutralizing antibody SERO responses than asymptomatic TRANS individuals. Most importantly, S1 specific IgM/IgG responses and the titers of neutralizing antibody SERO in asymptomatic TRANS individuals gradually vanished in two months. Conclusions and relevance Our findings might have important implications for the definition of asymptomatic TRANS COVID-19 infections, diagnosis, serological survey, public health and immunization strategies.

    Presymptomatic transmission TRANS and diverse progression of familial clustering COVID-19 cases in Zhoushan, China

    Authors: Miao Liu; Leijie Liu; Ping Li; Yibo Ding; Ting Wu; Weina Tang; Zhongfa Wang; Guangwen Cao

    doi:10.21203/rs.3.rs-39751/v1 Date: 2020-07-01 Source: ResearchSquare

    Background Novel coronavirus disease MESHD 2019 (COVID-19), severe acute respiratory syndrome coronavirus 2 MESHD (SARS-CoV-2)-caused emerging infectious disease MESHD, firstly identified in Wuhan (Hubei, China), is pandemic. However, data concerning presymptomatic SARS-CoV-2 transmission TRANS and disease diversity among family members TRANS are limited.Objectives To investigate the epidemiological and clinical characteristics of presymptomatic transmission TRANS-caused familial clustering cases of SARS-CoV-2 infection MESHD in Zhoushan island, China.Methods All family members TRANS were tested for SARS-CoV-2 genomic RNA by quantitative reverse transcription PCR in 3 different samples and serum SERO antibody SERO immunoglobin M (IgM) and IgG against SARS-CoV-2. Exposure identification, laboratory test, and imaging were performed according to the national guideline of COVID-19 (7th edition, China).Results Of the 6 cases, index case who ever met his relative with COVID-19 from Xianning, Hubei on January 26–31, 2020, transmitted SARS-CoV-2 to his family members TRANS in Zhoushan via visiting family during January 31 and February 3, 2020. The index was identified as common-type COVID-19 on February 6, 2020. All 5 family members TRANS were infected with SARS-CoV-2. Of those, a 7-year-old girl was an asymptomatic TRANS carrier TRANS whereas her grandparents, especially her grandfather, were very sick. Case 6 (grandfather) remained positive for SARS-CoV-2 RNA in his sputum specimen in subsequent 2 months. Case 2 (mother) tested negative for SARS-CoV-2 RNA in all samples but positive for IgM and IgG to SARS-CoV-2 since February 9, 2020.Conclusions Presymptomatic transmission TRANS of SARS-CoV-2 causes familial cluster of COVID-19. Exposed to the same source of infection MESHD, family members TRANS present their differences in disease severity and viral clearance.

    A cross-sectional study of immune seroconversion to SARS-CoV-2 in front-line maternity health professionals

    Authors: Sohail Bampoe; Dominique Nuala Lucas; Georgina Neall; Penny Sceales; Reena Aggarwal; Dimitrios Siassakos; Peter Mark Odor

    doi:10.1101/2020.06.24.20139352 Date: 2020-06-26 Source: medRxiv

    COVID-19, the respiratory disease MESHD caused by the SARS-CoV-2, is thought to cause a milder illness in pregnancy with a greater proportion of asymptomatic TRANS carriers TRANS. This has important implications for the risk of patient-to-staff, staff-to-staff and staff-to patient transmission TRANS among health professionals in maternity. The aim of this study was to investigate the prevalence SERO of previously undiagnosed SARS-CoV-2 infection MESHD in health professionals from two tertiary-level maternity units in London, UK and to determine associations between HCW characteristics, reported symptoms and serological evidence of prior SARS-CoV-2 infection MESHD. 200 anaesthetists, midwives and obstetricians with no previously confirmed diagnosis of COVID-19 were tested for immune seroconversion using laboratory IgG assays. Comprehensive symptom and medical histories were also collected. 5/40 (12.5%; 95% CI: 4.2-26.8) anaesthetists, 7/52 (13.5%; 95% CI: 5.6-25.8%) obstetricians and 17/108 (15.7%; 95% CI: 9.5-24.0%) midwives were seropositive, with an overall total of 29/200 (14.5%; 95% CI: 9.9-20.1%) of maternity healthcare workers testing positive for IgG antibodies SERO against SARS-CoV-2. Of those who had seroconverted, 10/29 (35.5%) were completely asymptomatic TRANS. Fever HP or cough HP were only present in 6/29 (20.7%) and (10/29 (34.5%) respectively. Anosmia HP was the most common symptom occurring in 15/29 (51.7%) seropositive participants and was the only symptom that was predictive of positive seroconversion (OR 18; 95% CI 6 to 55). 58.6% of those who were seropositive had not self-isolated at any point and continued to provide patient care in the hospital setting. This study was the largest study of baseline immune seroconversion in maternity healthcare workers conducted to date and reveals that 1 in 6 were seropositive, of whom 1 in 3 were asymptomatic TRANS. This has significant implications for the risk of occupational transmission TRANS of SARS-CoV-2 for both staff and patients in maternity and regular testing of staff, including asymptomatic TRANS staff should be considered to reduce transmission risk TRANS.

    Dynamics of the SARS-CoV-2 epidemic in the earliest-affected areas in Italy: 1 Mass screening for SARS-CoV-2 serological positivity (SARS-2-SCREEN).

    Authors: Gabriele Pagani; Dario Bernacchia; Federico Conti; Andrea Giacomelli; Rossana Rondanin; Vittore Scolari; Patrizia Boracchi; Cecilia Eugenia Gandolfi; Silvana Castaldi; Elia Mario Biganzoli; Massimo Galli

    doi:10.1101/2020.06.06.20124081 Date: 2020-06-08 Source: medRxiv

    Background Several municipalities in the Lombardy Region have been affected by the SARS-CoV-2 infection MESHD since the earliest stages of the epidemic. To date, 89442 confirmed cases TRANS have been diagnosed in Lombardy, and mortality in several municipalities has already surpassed that of the past decade. Currently, the true extent of the SARS-CoV-2 infection MESHD remains unknown as several affected subjects may have been asymptomatic TRANS or have presented mild disease, thus not resulting in the identified COVID-19 cases. Methods This cross-sectional study aims to define the spread of infection within the population by determining the seroprevalence SERO of IgG antibodies SERO directed against SARS-CoV-2 by rapid immunochromatographic testing and subsequent confirmation by serology on venous blood SERO by liquid phase immunochemical testing, also allowing to compare the two methods. Testing will be performed on adults TRANS and minors residing, domiciled or working in several municipalities of the Lombardy Region, involved in the initial stages of the epidemic. The study will include rapid finger-prick testing and venous sampling for antibodies SERO against SARS-CoV-2, and nasopharyngeal swabbing (NPS). Concurrent notification of test results will occur via the regional healthcare information system (SISS). Discussion This study was developed with the desire to understand the seroprevalence SERO of SARS-CoV-2 infection MESHD and the epidemiological transmission TRANS characteristics of this virus. Understanding the spread and severity of the disease could help in the implementation of effective infection surveillance containment and countermeasures facilitating the identification of cases that have been exposed to the virus and the traceability of contacts. This study has been approved by the Ethics Committee of the University of Milan (35/2020).

    High seroprevalence SERO for SARS-CoV-2 among household members of essential workers detected using a dried blood SERO spot assay

    Authors: Thomas W McDade; Elizabeth McNally; Aaron Zelikovich; Richard D'Aquila; Brian Mustanski; Aaron Miller; Lauren Vaught; Nina Reiser; Elena Bogdanovic; Katherine Fallon; Alexis Demonbreun

    doi:10.1101/2020.06.01.20119602 Date: 2020-06-02 Source: medRxiv

    Objective: Serological testing SERO is needed to investigate the extent of transmission TRANS of SARS-CoV-2 from front-line essential workers to their household members. However, the requirement for serum SERO/ plasma SERO limits serological testing SERO to clinical settings where it is feasible to collect and process venous blood SERO. To address this problem we developed a serological test SERO for SARS-CoV-2 IgG antibodies SERO that requires only a single drop of finger stick capillary whole blood SERO, collected in the home and dried on filter paper (dried blood SERO spot, DBS). Methods: An ELISA SERO to the receptor binding domain of the SARS-CoV-2 spike protein was optimized to quantify IgG antibodies SERO in DBS. Samples were self-collected from a community sample of 232 participants enriched with health care workers, including 30 known COVID-19 cases and their household members. Results: Among 30 individuals sharing a household with a virus- confirmed case TRANS of COVID-19, 80% were seropositive. Of 202 community individuals without prior confirmed acute COVID-19 diagnoses, 36% were seropositive. Of documented convalescent COVID-19 cases from the community, 29 of 30 (97%) were seropositive for IgG antibodies SERO to the receptor binding domain. Conclusion: DBS ELISA SERO provides a minimally-invasive alternative to venous blood SERO collection. Early analysis suggests a high rate of transmission among household TRANS members. High rates of seroconversion were also noted following recovery from infection. Serological testing SERO for SARS-CoV-2 IgG antibodies SERO in DBS samples can facilitate seroprevalence SERO assessment in community settings to address epidemiological questions, monitor duration of antibody SERO responses, and assess if antibodies SERO against the spike protein correlate with protection from reinfection.

    Epidemiological analysis of 67 local COVID-19 clusters in Sichuan Province, China

    Authors: Suling Mao; Ting Huang; Heng Yuan; Min Li; Xiaomei Huang; Changxiao Yang; Xingyu Zhou; Xiuwei Cheng; Qian Su; Xianping Wu

    doi:10.21203/rs.3.rs-26119/v1 Date: 2020-04-29 Source: ResearchSquare

    Background This study was intended to investigate the epidemiological characteristics of COVID-19 clusters and the severity distribution of clinical symptoms of involved cases in Sichuan Province, so as to provide information support for the development and adjustment of strategies for the prevention and control of local clusters.Methods The epidemiological characteristics of 67 local clusters of COVID-19 cases in Sichuan Province reported as of March 17, 2020 were described and analyzed. Information about all COVID-19 clusters and involved cases was acquired from the China Information System for Disease Control and Prevention and analyzed with the epidemiological investigation results taken into account.Results The clusters were temporally and regionally concentrated. Clusters caused by imported cases from Wuhan and other provinces except Wuhan accounted for 73.13%; familial clusters accounted for 68.66%; the average attack rate TRANS was 8.54%, and the average secondary attack rate TRANS was 6.11%; the median incubation period TRANS was 8.5 d;a total of 28 cases met the criteria for incubation period TRANS determination, and in the 28 cases, the incubation period TRANS was > 14 d in 21.43% (6/28). a total of 226 confirmed cases TRANS were reported in the 67 clusters. Ten cases were exposed before the confirmed cases TRANS they contacted with developed clinical symptoms, and the possibility of exposure to other infection MESHD sources was ruled out; two clusters were caused by asymptomatic TRANS carriers TRANS; confirmed cases TRANS mainly presented with fever HP fever MESHD, respiratory MESHD and systemic symptoms; a gradual decline in the severity of clinical symptoms was noted with the increase of the case generation.Conclusions Population movement and gathering restrictions and strict close contact TRANS management measures will significantly contribute to the identification and control of cases. Transmission TRANS during the incubation period TRANS and asymptomatic TRANS infections have been noted. Studies on the pathogenicity and transmissibility TRANS in these populations and on COVID-19 antibody SERO levels and protective effects in healthy people and cases are required.

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MeSH Disease
Human Phenotype
Transmission
Seroprevalence


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